On Fri, Aug 1, 2008 at 6:31 PM, Eric Brombaugh <address@hidden> wrote:
On Aug 1, 2008, at 1:58 PM, Philip Balister wrote:
I've been talking to a friend (he knows FPGA stuff much better than
me) about using the expansion port to communicate with an FPGA via a
SDIO interface. I don't think we can beat the current USRP data rate,
but we should be able to reduce the latency introduced by the USB
interface.
Looks like the SDIO ports run up to 50MHz and have 8-bit wide data. No idea
how much overhead there is in that, but it might be able to go a bit faster
than USB2.0 and as you note would have a lot less latency. Hook up to a
decent FPGA and you could cram a bit of external pre-processing in as well.
I picked up one of the Avnet Xilinx Spartan 3A boards for $50 that would
probably work well for that.
We are hoping to create a board with a reasonable FPGA that works with
existing USRP daughterboards. This would make a really neat system for
small SDR nodes. I'll be sure to keep you updated on out progress.
Using an existing dev board for developing the beagle to FPGA
interface is a really good idea, thanks for suggesting it!
Philip